The proposal

Eliminate the legal waiver that allows states such as California to set higher standards

National average car mileage

The Corporate Average Fuel Economy standards are regulations enacted by Congress in 1975, after the 1973-74 Arab Oil Embargo, to improve the average fuel economy of cars and light trucks made in the U.S.

Cars that get 40-plus mpg

The number of cars with gas mileage of 40 mpg or greater is more than eight times more than the number in 1990. The chart below shows how many cars with 40 mpg on the highway by year from fueleconomy.gov. The list does not include variations of the same model such as a coupe and a wagon of the same model. Electric vehicles are included based on what’s known as gas equivalent.Fuel economy data are the result of vehicle testing done at the Environmental Protection Agency’s National Vehicle and Fuel Emissions Laboratory in Ann Arbor, Michigan, and by vehicle manufacturers with oversight by EPA.

Kurt Snibbe is a visual journalist for Southern California News Group. Snibbe has won several medals in international graphics competitions and was a staff cartoonist for ESPN.com. Snibbe began with The Orange County Register in 1997, left in 2008 and returned in 2013.